Reduced diameter indoor fiber optic cable

Abstract

Tight buffered optical fiber cables for indoor use as jumper or interconnect cables have a reduced outer diameter and nonetheless pass many recognized mechanical and environmental test procedures. A single optical fiber cable has an outer diameter of equal to or less than 1500 mu m, and a dual optical fiber cable has an outer diameter of equal to or less than 2000 mu m. A layer of loose tensile strength yarn is disposed between the tight buffered optical fiber or optical fibers and the outer jacket. The cables may be made of flame retardant materials for riser or plenum applications.

What is claimed is: 
     
       1. An optical fiber cable, comprising: a single optical waveguide fiber having an outer coating, said outer coating having a diameter of about 500 μm;   a layer of loose tensile fibers surrounding the optical waveguide fiber outer coating; and,   a tubular jacket of plastic material having an outer diameter D 2  surrounding the layer of loose tensile fibers, D 2  not exceeding about 1500 μm, said cable containing no gel-like compounds.   
     
     
       2. An optical fiber cable as set out in claim 1, wherein D 2  does not exceed about 1400 μm. 
     
     
       3. An optical fiber cable as set out in claim 1, wherein D 2  does not exceed about 1200 μm. 
     
     
       4. An optical fiber cable as set out in claim 1, wherein the optical fiber cable outer jacket is formed of flame-retardant material. 
     
     
       5. An optical fiber cable as set out in claim 1, wherein the optical waveguide fiber outer coating is made of plastic material having a Shore 15 seconds hardness rating of at least about 58 on the D scale. 
     
     
       6. An optical fiber cable as set out in claim 1, wherein the optical fiber cable jacket is made of plastic material having a Shore 15 seconds hardness rating of at least about 67 on the C scale. 
     
     
       7. An optical fiber cable as set out in claim 1, wherein the tubular jacket has an inner diameter D 1  and (D 2  -D 1 ) is less than or equal to about 300 μm. 
     
     
       8. An optical fiber cable as set out in claim 1 which contains no materials comprising halogen compounds. 
     
     
       9. An optical fiber cable as set out in claim 1 which contains no materials comprising leaded compounds. 
     
     
       10. An optical fiber cable, comprising: a single optical waveguide fiber having an outer coating, said outer coating having a diameter of about 500 μm;   a layer of loose tensile fibers surrounding the optical waveguide fiber outer coating; and,   a tubular jacket of plastic material having an outer diameter D 2  surrounding the layer of loose tensile fibers, D 2 , not exceeding about 1500 μm, said cable passing the ANSI-596 Crush test.   
     
     
       11. An optical fiber cable, comprising: two optical waveguide fibers each having an outer coating, each said outer coating having a diameter of about 500 μm;   a layer of loose tensile fibers surrounding the coated optical waveguide fibers; and,   a tubular jacket of plastic material having an outer diameter D 2  surrounding the layer of loose tensile fibers, D 2  not exceeding about 2000 μm. said cable containing no gel-like compounds.   
     
     
       12. An optical fiber cable as set out in claim 11, wherein D 2  does not exceed about 1800 μm. 
     
     
       13. An optical fiber cable as set out in claim 11, wherein D 2  does not exceed about 1600 μm. 
     
     
       14. An optical fiber cable as set out in claim 11, wherein the optical fiber cable outer jacket is formed of flame-retardant material. 
     
     
       15. An optical fiber cable as set out in claim 11, wherein the optical waveguide fiber outer coatings are made of plastic material or materials having a Shore 15 seconds hardness rating of at least about 58 on the D scale. 
     
     
       16. An optical fiber cable as set out in claim 11, wherein the optical fiber cable jacket is made of plastic material having a Shore 15 seconds hardness rating of at least about 67 on the C scale. 
     
     
       17. An optical fiber cable as set out in claim 11 which contains no materials comprising halogen compounds. 
     
     
       18. An optical fiber cable as set out in claim 11 which contains no materials comprising leaded compounds. 
     
     
       19. An optical fiber cable as set out in claim 11, wherein the tubular jacket has an inner diameter D 1  and (D 2  -D 1 ) is less than or equal to about 300 μm. 
     
     
       20. An optical fiber cable, comprising: two optical waveguide fibers each having an outer coating, each said outer coating having a diameter of about 500 μm;   a layer of loose tensile fibers surrounding the coated optical waveguide fibers; and,   a tubular jacket of plastic material having an outer diameter D 2  surrounding the layer of loose tensile fibers, D 2  not exceeding about 2000 μm, said cable passing the ANSI-596 Crush test.